Wood material board with reduced emission of volatile organic compounds (VOCs) and method for the production thereof

Abstract

A method for producing wood material boards with reduced emission of volatile organic compounds (VOCs), including: a) producing woodchips from suitable timbers; b) heat-treating at least one portion of the woodchips at a temperature between 150° C. and 300° C. for a period of 1 to 5 hours; c) crushing the wood chips that are not heat-treated and at least one portion of the heat-treated woodchips by machining in order to obtain wood shavings or by solubilizing in order to obtain wood fibers; d) gluing the wood shavings or wood fibers with at least one binding agent; e) applying the glued wood shavings onto a transport belt while forming a multi-layered shavings cake or applying the glued wood fibers onto a transport belt while forming a single-layer fiber cake; and f) compressing the shavings cake or the fiber cake to form a wood material board.

The invention claimed is: 
     
       1. A process for producing woodbase panels with reduced emission of volatile organic compounds (VOCs), comprising:
 a) producing wood chips from suitable lumbers, 
 b) heat-treating at least a part of the wood chips by heating in an oxygen-depleted or oxygen-free environment at a temperature between 150° C. and 300° C. over a period of 1 h to 5 h; 
 c) comminuting the non-heat-treated wood chips and at least a part of the heat-treated wood chips by shaving to give wood shavings or by digesting to give wood fibers; 
 d) resinating the wood shavings or wood fibers with at least one binder, wherein the wood shavings or wood fibers have been produced from the heat-treated and the non-heat-treated wood chips according to step (c); 
 e) applying the resinated wood shavings to a conveyor belt, to form a multilayer shaving cake, or applying the resinated wood fibers to a conveyor belt, to form a single-layer fiber cake; and 
 f) compressing the shaving cake or the fiber cake to form a woodbase panel. 
 
     
     
       2. The process as claimed in  claim 1 , wherein the step of heat-treating the wood chips is integrated into the operation of producing the woodbase panel. 
     
     
       3. The process as claimed in  claim 1 , wherein the step of heat-treating the wood chips is carried out separately from the operation of producing the woodbase panel. 
     
     
       4. The process as claimed in  claim 1 , wherein the wood chips are heat-treated at temperatures between 200° C. and 280° C. 
     
     
       5. The process as claimed in  claim 1 , wherein the wood chips are heat-treated over a period between 2 h and 3 h. 
     
     
       6. The process as claimed in  claim 1 , wherein the wood chips are heat-treated by heating in an oxygen-depleted or oxygen-free atmosphere. 
     
     
       7. The process as claimed in  claim 1 , wherein at least a part of the wood chips with a moisture content of 20-50 wt % are heat-treated. 
     
     
       8. The process as claimed in  claim 1 , wherein the heat-treated wood chips are cooled in a water bath, the water being admixed with at least one wetting agent. 
     
     
       9. The process as claimed in  claim 1 , wherein the moisture content of the heat-treated chips is adjusted to 5% to 20%. 
     
     
       10. The process as claimed in  claim 6 , wherein the wood chips are heat-treated by heating in a saturated steam atmosphere. 
     
     
       11. The process as claimed in  claim 9 , wherein the moisture content of the heat-treated chips is adjusted to 10% to 15%. 
     
     
       12. The process as claimed in  claim 4 , wherein the wood chips are heat-treated at temperatures between 220° C. and 260° C. 
     
     
       13. The process as claimed in  claim 1 , wherein the woodbase panels are wood chipboard or wood fiberboard panels. 
     
     
       14. The process as claimed in  claim 2 , wherein the wood chips are heat-treated at temperatures between 200° C. and 280° C.